The present invention relates to heavy metal alloys and in particular to a tungsten alloy whose strength and hardness properties are improved by the inclusion of tantalum.
Classic tungsten heavy alloys include about 90% by weight tungsten with nickel and iron added in a ratio of about 7 to 3.
Tungsten heavy alloys have an attractive combination of properties including high density, high strength, high ductility and easy machinability. This makes tungsten alloys very useful for applications such as radiation shields, counterbalances, heavy duty electrical contacts, vibration dampers and kinetic energy penetrators. The usefulness of the alloy, in particular when used as kinetic energy penetrators, can be enhanced if its strength and hardness properties are increased. Even a relatively small increase in strength and hardness, for example 1% or 2% would be advantageous.
Some attempts have been made to improve the strength of alloys by adding cobalt, chromium, rhenium, platinum, titanium, small amounts of molybdenum and aluminum. These attempts have met with very little success however.
Rather than improving the hardness characteristics of heavy alloys, kinetic energy penetrators, especially those used for piercing heavy armor plates, have been made with depleted uranium as an important constituent. This material is, of course, highly toxic and expensive. It would, therefore, by very desirable if a heavy alloy could be developed having substantially increased hardness and strength characteristics.